This topic outlines how to write a mediation handler, add
mediation function to it, and prepare it for installation on an application
server.
Before you begin
Before you start this task, you should have access to a Java™ programming environment, and
the Eclipse development environment (part of the Application Server
Toolkit supplied with WebSphere® Application
Server.)
About this task
A mediation handler can be deployed. Each mediation handler
executes some specific message processing at runtime, for example
transforming a message format, or routing a message to a particular
destination. A mediation handler is a Java program
framework, to which you add the code that performs the mediation function.
For more information about handlers, see Mediation handlers and mediation handler lists.
Your
mediation handler class can be defined either in a Java project or an EJB project (which is needed
for the deployment artefact.) Your programming and deployment artefacts
can be separated in different projects. The steps below are for an
EJB project, but the steps are very similar if you want to create
a Java project, since you simply
define a target server for either a Java project
or an EJB project and the server runtime plug-in sets the class path
correctly.
Procedure
- Create a new EJB project:
- Switch to the J2EE perspective to work with J2EE projects.
Click Window > Open Perspective > Other >J2EE.
- From the File menu, select New > Project.
- Expand the J2EE folder, and select Enterprise Application
Project. Click Next.
- Optional: If you have created a Java project instead of an EJB project, right
click on the Java project folder
icon for the context menu and select Properties. When the Properties
panel appears, select the Server properties and target the project
to WebSphere Application
Server Version 6.0, as in the next step.
- Enter a name for the project and target the project
to WebSphere Application
Server Version 6.0. (If this is the first time you target this server
you will need to click the New... button.)
Click Next to take you to the EAR
Module Projects window.
- Click New Module....
- Create a new module project by selecting the check box
against EJB project, and entering the name of your mediation handler.
- Click Finish. You
are returned to the EAR Module Projects window.
- Click Finish to create the new
project.
- Create a mediation handler class by implementing the com.ibm.websphere.sib.mediation.handler.MediationHandler
interface.
- From the File menu, select New > Java Class.
- Specify the source folder for your mediation EAR project.
- Specify a name for your mediation handler.
- Select Superclass java.lang.Object.
- Select Interface com.ibm.websphere.sib.mediation.handler.MediationHandler.
- Click in the check box to select Inherited abstract
methods
- Click Finish to create the new
mediation handler class.
- Add functional code that transforms or routes messages
to your mediation handler using the Application Server Toolkit. For
more information, see Adding mediation function to handler code.
Beware that the default return value for the handle method created
by the toolkit is false, which causes
the message to be discarded. You need to change the return value to true to
preserve the message.
- Generate an EAR file from your mediation handler class.
Follow the instructions in the topic entitled "Deploying a mediation
handler" in the Application Server Toolkit information center.
Note that the Application Server Toolkit is also available in
the Rational® Software Development
Platform.
What to do next
Next, you are ready to install the EAR file containing your
mediation handler into the application server.